Oxygen generator assemblies utilizing chlorate candles are well known in the art and typical examples are U.S. patents 2,558,756, 3,536,070 and 4,687,640. These assemblies include a chlorate candle which is mounted in a containment vessel, both of which are typically cylindrical. The chlorate candles typically include sodium chlorate, or an equivalent chlorate or perchlorate which is capable of releasing oxygen when heated. The chlorate is typically mixed with an oxidizable element such as iron or carbon, a binder, and a peroxide for scrubbing chlorine from the gases released during combustion, the mixture of the various elements forming a pyrotechnic mix which is typically pressed into a cylindrical block. Oxygen is released during the heating of the sodium chlorate in accordance with the following reaction: EQU 2NaClO.sub.3 .fwdarw.3O.sub.2 +2NaCl
A typical mix may include 80% sodium chlorate, 10% iron powder, 4% Barium peroxide, and the balance being a binder such as glass fibers.
The various compositions of chlorate candles are well known in the art and the compositions may be varied to meet specific requirements.
It is well known from the prior art that the rate of oxygen output of a chlorate candle is a function of the inherent burn rate of the pyrotechnic mix, the burning area, and the surrounding temperature. In the prior art designs, the cylindrical chlorate candle is ignited at one end and, once ignited, the chlorate candle will continue to burn in a plane perpendicular to its axis. The cylindrical diameter conventionally determines the burning area available. A small generator assembly which is designed for high flow output would require either a large diameter compared to its length, or it would require a very fast burning pyrotechnic mix. There are practical limitations on how fast a candle can be made to burn. High heat flux and decreased efficiency are the consequences of adding a fuel to accelerate the burn. Practical considerations tend to limit the oxygen output to 20 liters per minute per square inch of burn area. Limitations to enlarging the diameter arise as the expanding diameter causes the configuration to approach a disk. In this case, the containment vessel of such a generator assembly configuration becomes unwieldly or incapable of containing pressure at a reasonable weight.
It is also known from the prior art that the pressed cylindrical block of sodium chlorate pyrotechnic material may be provided with a conical recess which in turn receives a conical plug of loose ignition material. In such prior art the burning is designed to progress in a substantially axially direction to achieve a relatively low oxygen flow.